Jaime goes undercover with a deadly human trafficking ring. Danny and Baez investigate a homicide connected to Darryl Reid, Danny's old partner. Also, Frank grapples with whether to publicly support Mayor Chase on a policy decision and Eddie is determined to teach a young shoplifter a lesson.

Frank grapples with the personal loss of his best friend and how best to help Tess Ross, the daughter of his best friend, when she lands in jail. Also, Jaime and his nephew, Joe Hill, race against the clock to reunite a trafficking victim with her sister; and Danny and Erin clash when she goes behind Danny's back to use his criminal informant in an investigation.